Galv Savvy - helps get the initial kill to start chain reaction, but not sure if it scales into toxic lash at full damage bonus. Most of the +dmg will be from primary merciless so this slot may be replaceable with shotgun spazz or more elemental mods such as chilling reload or a 90% elemental.

Primed Cleanse Grineer - faction mods TRIPLE DIP on toxic lash toxin procs by boosting your weapon damage, boosting toxic lash damage on hit (which scales off weapon damage) and boosting toxic DoT (which sclaes off the first two).

Toxic Barrage and Contagious Spread - Toxin mods DOUBLE DIP on toxic lash procs by multiplying the toxic lash damage and toxic DoTs

Primed Chilling Grasp and Primed Charged Shell - elemental mods boost weapon damage which increases both the initial toxic lash damage and the resulting DoT

If you are NOT using [Saryn] with Toxic Lash, you can drop [Contagious Spread] for Shotgun Spazz or [Primed Point Blank]. [Primed Charged Shell] is also flexible if you are not using grouping or armor strip.

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